B 437 Weserquerung und Wesertunnel Besonderheiten und Erfahrungen

From 1998 to the end of 2003 the Weser Tunnel at Kleinensiel / Dedesdorf was built as the first firm road connection between both sides of the Lower Weser. At this, the 1.636 m long twin-tube tunnel forms undoubtedly the main part of this important building project to improve the transport infrastructure. New roads 15 km of length and 20 bridges complete the connection of the tunnel to the existing road network. The special features of the Weser Tunnel are not the large diameter of 11.67 m but rather the geological and geohydrological boundary conditions. Nonhomogeneous grounds with large settlements and the dependence on the tide stroke put large challenges on man and machine. The driving of the south tube was characterized by stickings of cohesive soils, blow-outs and suspension losses and frequent standstills. Due to several modifications of the machine and the working process the north tube passed almost without any difficulties. Similar findings were made for the construction of the new connection roads and the 20 bridges as well.